1. Field of the Invention
The present invention relates to an image reading apparatus having sheet conveying device.
Moreover, the present invention relates to an image reading device, particularly to an image reading device, for example, which has a reading section detachably attached to a device body and an openable/closable operating section.
Furthermore, the present invention relates to an image reading device, particularly to an image reading device which is provided, for example, with recording means for recording an image on a recording sheet, or a rolled sheet storage section for feeding the recording sheet to recording means, below separating means for conveying a document to reading means.
Additionally, the present invention relates to an image reading device, particularly to an image reading device which is provided, for example, with a reading section for taking in an image of document, and which is applied to a facsimile machine, a copying machine, a scanner, and the like.
2. Related Background Art
A conventional image reading device of a printer, a copying machine, a facsimile machine, and the like will be described with reference to FIGS. 35 to 38.
Additionally, also according to the present invention, in the image reading device, sheets are conveyed. Examples of the sheets include paper, a thin resin sheet as a substitute for the paper, a post card, a board, a letter, a thin plastic plate, and the like. An example where the paper is conveyed will be described.
In the drawings, a separating piece 1102 is disposed opposite to a separating roller 1101, and pressed onto the separating roller 1101 by spring means 1103. The separating roller 1101 and separating piece 1102 separate and convey a plurality of sheets of document sheet by sheet.
Numeral 1104 denotes a conveying roller for determining the conveying speed of the document. A conveying roller 1105 is rotatably attached so as to hold and convey the document with the conveying roller 1104. Additionally, numeral 1106 denotes a discharging roller for holding the document with a discharging roller 1107 to discharge the document to the outside of a body.
Numeral 1108 denotes an upper document guide for guiding the document, numeral 1109 denotes a lower document guide, and numeral 1110 denotes a reading unit for reading the image of the conveyed document. The separating piece 1102, conveying roller 1105, and discharging roller 1107 are attached to the upper document guide 1108. The separating roller 1101, the conveying roller 1104, the discharging roller 1106, and a motor 1111 for operating the rollers are attached to a frame via a drive substrate 1112.
On the other hand, the upper document guide 1108 is rotatably supported on a protrusion formed on the frame as a support point to open and close using a document path as a boundary so that document jam handling, and cleaning of an image processing device can be performed. Specifically, as shown in FIG. 38, by unlocking a lock (not shown) to rotate the upper document guide 1108 upward, abutment states of the separating roller 1101 and separating piece 1102, the conveying rollers 1104 and 1105, and the discharging rollers 1106 and 1107 can be released. Thereby, the document stopped halfway during conveying can easily be removed by a user.
The operation of the rollers will next be described.
The conveying roller 1104 is constituted of a metal shaft 1104a and a rubber portion 1104b. The rubber portion 1104b is bonded to the metal shaft 1104a to integrally rotate with the metal shaft 1104a. To one end of the metal shaft 1104a, a feeding roller gear 1113 is attached so as to integrally rotate with the metal shaft 1104a. The feeding roller gear 1113 is connected to the reading motor 1111 via reduction gears 1114, 1115, so that it rotates at a reduction ratio N with respect to a step angle of the reading motor 1111.
In the same manner as the conveying roller 1104, the discharging roller 1106 is constituted of a metal shaft 1106a and a rubber portion 1106b. A discharging roller gear 1116 attached to one end of the metal shaft 1106a is connected to the motor 1111 via reduction gears 1117, 1115.
The separating roller 1101 is constituted of a holder portion 1101a and a rubber portion 1101b. A protrusion 1118 is formed on the end surface of the holder portion 1101a. To a separating roller shaft 1119 a disk-shaped mechanical timer 1120 provided with a protrusion 1120a is attached so as to integrally rotate with the shaft 1119.
The protrusions 1118 and 1120a are formed to be in the same position in a radial direction, so that when the separating roller 1101 is attached to the separating roller shaft 1119 and rotated, a play only of a constant angle is formed between the shaft 1119 and the roller 1101.
Moreover, attached to one end of the separating roller shaft 1119 is a separating roller gear 1121 which incorporates a one-way clutch to transmit drive only in one direction. Therefore, the rotating force of the reading motor 1111 is transmitted to the shaft only in a document conveying direction. The separating roller gear 1121 is connected to the motor 1111 via a connecting gear 1122, the conveying roller gear 1113, and the reduction gears 1114, 1115. The separating roller gear 1121 is rotated in the same direction as the conveying roller 1104 by the drive force of the motor 1111.
As shown in FIG. 38, the conventional image reading device 1100 can be opened/closed on the boundary of the document path. The separating piece 1102 and the separating roller 1101 are separately supported by the upper document guide 1108 and the member of the frame. Therefore, since it is very difficult to manage a positional relation between the separating piece 1102 and the separating roller 1101 and the spring state, there is a problem that sheet separating performance is unstable.
Moreover, for the conventional image reading device 1100, three drive rollers of the separating roller 1101, conveying roller 1104 and discharging roller 1106, and the reading motor 1111 are all arranged in the frame, and the positional relation among shafts can be managed by the dimension of a support portion on the frame. When the gears are interconnected, a highly efficient and precise sheet conveying system can be formed. However, when this constitution is incorporated in a reading/conveying system having a hand scanner, the discharging roller 1106 is disposed in the hand scanner. Therefore, it becomes necessary to disconnectably connect the drive of the discharging roller 1106 with the drive system of the sheet conveying device body, and there arises a problem that the highly efficient and precise sheet conveying system cannot be provided.
Furthermore, even if the highly efficient and precise sheet conveying system can be constituted, there is another problem that the number of components is increased and cost is also increased.
Additionally, in recent years, it has been desired that the image reading device should be able to read thin sheet documents as well as thick documents such as brochures and books. Moreover, there is a demand for means for removing the document from the device body when the reading operation of the device is abnormally stopped halfway.
As examples of the means to attain the reading operation of the thick documents for the image scanner, the copying machine, and the like, many constitutions comprise disposing a document base, laying on the document base the sheet documents or the thick documents such as brochures and books, and moving the document base itself or an image sensor as reading means, to read image information of the documents.
In the image reading device in which the device body is compact and easily operable, however, it is difficult to dispose a large document base. Therefore, in recent years, to attain the above-described demand, other structure has been increasingly proposed as follows. For example, in a small-size facsimile device, when the thin sheet document is read, a reading section is disposed in the device body, and image information is read by conveying the sheet document. When the brochure, the book, or another thick document is read, some constitutions comprise detaching the reading section from the device body, allowing the reading section to scan on an image plane to be read of the brochure, the book, and the like, and reading the document image information.
Moreover, to remove the document during abnormal stop, in the image scanner or the copying machine, by opening a document base cover, the document may be removed from the document base.
However, in small-size image reading devices such as a small-size facsimile device, a document conveying path is constituted of upper and lower document guide members. Many constitutions comprise moving the upper document guide member by rotating movement or parallel movement to open the reading document conveying path, and removing the document when the document is abnormally stopped halfway during reading operation.
Here, in the image reading device, white reference data is necessary for judging density during image reading, but in the small-size facsimile device, a white reference member for reading the white reference data is disposed in the opposite portion of the image reading device with respect to the document conveying path in many cases. When the sheet document is conveyed into the device body to read the image information, by reading the white reference member every time the reading operation is performed, the white reference data is taken. Moreover, when the reading section detached from the device body is allowed to scan on the reading image surface to read the image information, the white reference data before detaching the reading section from the device body is frequently used. Therefore, in many cases, the white reference data is usually read when power supply is turned on, so that the reading section can be detached from the device body at any time to perform the reading operation.
Here, first, assuming that the device body cannot recognize whether or not the attachable/detachable reading section is attached to the device body, in the operation of reading the sheet document while the detachable/attachable reading section is detached from the device body, the document is not conveyed onto the reading section, so that the image information cannot be read. Moreover, the document conveying is performed while no reading section is disposed in the document conveying path, and there is a defect that improper conveying, and the like could be generated. Moreover, when the reading section is detached from the device body, and power supply is turned on, there is a defect that the white reference data cannot be taken. Because no white reference member is disposed on the reading device.
Moreover, assuming that the upper document guide is moved, the device body cannot recognize whether or not the document conveying path is opened, but the document conveying path is opened, by turning on the power supply, the white reference member itself is detached from the image reading device, or the reading document conveying path is opened. In this case, exterior light enters the image reading face of the image reading device, which cases a defect that the white reference data cannot sufficiently be taken.
As the countermeasure of the defect, there is proposed a constitution which comprises a reading section presence/absence detecting sensor for detecting whether the reading section is attached/detached, and a document guide opening/closing detecting sensor for detecting whether the document conveying path is opened, so that the device body recognizes whether or not the detachable/attachable reading section is attached to the device body, or whether or not the document conveying path is opened.
However, in the above-described conventional constitution, each of the reading section presence/absence detecting sensor and the document guide opening/closing detecting sensor requires a sensor body, a mechanical component for turning on/off the sensor, an electric circuit around the sensor, wiring for transmitting a sensor ON/OFF signal to the device body, and many other components. The cost increase of the device body cannot be avoided, which also causes a defect that the assembling property and compactness of the device body are deteriorated.
Moreover, one example of the image reading device according to the related art proposed by the present applicant will be described with reference to sectional views of FIGS. 39 and 40.
First, the entire constitution comprises a reading section A′ for optically reading the document; a recording section B′ as an ink jet recording device; a recording sheet feeding section C′ for separating stacked recording sheets and feeding the sheets to a recording unit; a document feeding section D′ for separating stacked document sheets and conveying the sheets to a reading unit; and an operating unit E′ of FIG. 6 which operates functions, and which is opened during the jam handling of document S, the cleaning operation of the reading section A′, the jam handling of recording sheet P, and the replacement of an ink jet head 3105a and an ink tank 3105b in the recording section B′.
Next, the flow of the recording sheet P will briefly be described. A recording sheet conveying path is shown by an arrow F. Specifically, the recording sheet P stacked on a stacking tray 3101 and a pressure plate 3102 of the recording sheet feeding section C′ is picked up by a feeding roller 3103, and fed into the recording unit B′ by a pair of feeding rollers 3104a, 3104b. 
In the recording section B′ recording is performed by the ink jet head 3105a as recording means, and the sheet is conveyed by a certain distance in the device, then discharged/stacked by a pair of discharging rollers 3106a, 3106b, and a pair of discharging rollers 3107a, 3107b as discharging means.
Next, the flow of the document S will briefly be described. A document conveying path is shown by an arrow G.
In FIG. 39, the document feeding section D′ has a lower document guide face 3161 on which the document S is stacked with its image facing downward. In this case, even when the document S is longitudinal, it can be held by the stacking tray 3101. Specifically, the stacking tray 3101 has a role of stacking both the recording sheet and the document thereon. The document S stacked on the lower document guide face 3161 is positioned by a document slider 3151 which is disposed on the lower document guide face 3161 and which is movable in a width direction. One or a plurality of stacked sheets of document S are struck and set onto a portion surrounded by a friction piece 3152 disposed on an upper document guide 3165 and a separating roller 3153 attached to a lower document guide 3162. The friction piece 3152 is pressed downward from above by a friction piece spring 3158 and is on standby while pressing the separating roller 3153. When a signal for conveying the document S is sensed, the separating roller 3153 is rotated by drive of a motor (not shown). By cooperating action with the friction piece 3152 only the bottom document S is conveyed in the direction of arrow G and the document is successively conveyed to the reading section A′ sheet by sheet. The document S conveyed to the reading section A′ is conveyed to a document edge sensor 3155 and a photoelectric conversion sensor 3157 by the cooperating action of feeding rollers 3154a and 3154b. The photoelectric conversion sensor 3157 is energized along a reading line by a reading white base 3164, so that the image of the conveyed document S closely abuts on the reading line. Furthermore, the feeding roller 3154a determines the recording speed in a sub-scanning direction of document S, and conveys the document to discharging rollers 3156a and 3156b. Subsequently, the read document S is discharged by the discharging rollers 3156a and 3156b. 
The constitution of the operating unit E′ will next be described with reference to FIG. 40. As shown in FIG. 40, the top surface of the operating unit E′ is provided with keys and slide SWs (not shown) for operating functions and display elements (not shown) of LED and LCD. Moreover, the under surface of the operating unit E′ is provided with the upper document guide 3165 to form the conveying path of the document S. Furthermore, on the upstream side of the friction piece 3152, a sensor 3159 for detecting the presence/absence of the document S and a sensor 3160 for detecting the size of the document S are disposed. On the other hand, in the reading section A′ of the upper document guide 3165 the feeding roller 3154b and the discharging roller 3156b are attached and pressed downward from above by a roller pressing spring 3167. Moreover, as described above, the reading white base 3164 is disposed between the feeding roller 3154b and the discharging roller 3156b to serve as white reference during document reading. The operating unit E′ constituted as described above can be opened in a direction shown in FIG. 40 (front to rear) centering on a hinge portion 3165a as a rotating center which is a part of the upper document guide 3165 and positioned in the rear of the body, and the opened operating unit E′ is held by an operating section support arm (not shown). Moreover, when the operating unit E′ is closed, the operating unit E′ is locked in a normal position by a lock arm (not shown), and the like to maintain the pressing forces of the separating roller 3153 and friction piece 3152, the feeding rollers 3154a and 3154b, and the discharging rollers 3156a and 3156b at constant values.
The arrangement relation of the document feeding section D′, the reading section A′ and the recording section B′ will next be described with reference to FIGS. 39 and 40. As described above, both the document S and the recording sheet P flow in substantially parallel paths from the body rear side of a sheet feeding port to the body front side of a sheet discharge port. Moreover, in the recording section B′, for the replacing operation of the ink jet head 3105a and the ink tank 3105b, the jam handling operation of the recording sheet P, and the like, an operation space needs to be provided above the recording section B′. Therefore, above the recording section B′, the separating roller 3153 and friction piece 3152 of the document feeding section D′ and the reading section A′ are not arranged, and they are arranged before the recording section B′.
Here, the operating methods for the replacement of the ink jet head 3105a and the ink tank 3105b and the jam handling of the document S and the recording sheet P will be described with reference to FIG. 40.
An operator first rotates the operating unit E′ in a direction of arrow M centering on the hinge 3165a, until it is locked by the lock arm (not shown). In this case, a recording cover section 3166 constituted by a part of the lower document guide face 3161 disposed above the recording section B′ appears. By rotating the section as shown in FIG. 40, the portion above the recording section B′ is opened to form a space. Subsequently, a cartridge replacement key (not shown) disposed on the lower document guide 3161 is depressed to move the ink jet head 3105a and the ink tank 3105b (usually on standby in a position where no recording cover section 3166 is disposed above) to below the recording cover section 3166, so that the replacing operation is performed in the space. Furthermore, in this state the jam handling of the document S and recording sheet P can be performed.
In the above-described related art, when the operator replaces every ink jet head or only the ink tank, or performs the jam handling of the recording sheet, it is difficult to perform the replacing operation from the front part of the body. Because on the body front side the document feeding section and the reading section are arranged, and the recording section is disposed on the body rear side. Similarly, it is difficult to perform the recording sheet jam handling.
Moreover, in the related art, since the document feeding section and reading section are arranged on the body front side and the recording section is disposed on the body rear side, the depth of the device body is increased, and the installation area is enlarged.
Furthermore, in the related art, since the document feeding section and reading section are arranged on the body front side and the recording section is disposed in the vicinity, and both the document feeding section and the reading section are arranged in parallel above a recording sheet discharge port, space is narrow in the vicinity of the discharge port, and the recording sheet jam is easily generated.
Additionally, in the related art, when the documents are set, the operating unit is opened for the replacing operation of the ink jet head or the ink tank, the jam handling operation of the recording sheet or the cleaning operation of the reading section. In this case, since the document is an obstruction, the document needs to be once removed during the operations, which deteriorates the operation efficiency.
Furthermore, the facsimile machine as the image reading device has spread substantially completely to general companies, and in recent years, has increasingly spread broadly also to general household. In the companies where the sheet documents of A4 size or another fixed size need to be read in large amounts at once, there has been a large demand for the facsimile machine having a large-capacity high-speed automatic document feeder (ADF). In the general household, however, since the documents are seldom read in large amounts once, the ADF does not need a very large capacity. Rather, there are strong demands for the facsimile machine which can read various documents such as newspaper and other large-size documents, documents of unfixed forms, and books, magazines and other documents which cannot be passed through the ADF. To meet these demands, a so-called hand scanner system is widely used, which is constituted so that a reading section can be attached to/detached from a facsimile device body. Therefore, by manually scanning the document which cannot be passed through the ADF by a hand scanner detached from the body, image can be read.
FIGS. 41 and 42 are sectional views for describing the facsimile machine which has the conventional hand scanner. The facsimile machine comprises a facsimile device 9901; a document reading section 9902 for reading image information of a document; a hand scanner 9903 which can be attached to/detached from the facsimile device 9901 and which is provided with the document reading section 9902; a recording section 9904 for recording received data (or data read by the machine) onto recording sheets; an operating section 9905 in which switches (not shown) for operating the device are collected; and an ADF section 9906 driven by a drive source (not shown) for separating and conveying the document sheet by sheet to the reading section 9902 of the hand scanner 9903. Character G denotes the document set on the upper portion of the device, K denotes the recording sheet set inside the device, and arrows H and T indicate conveying paths of the document G and recording sheet K. The document G is separated sheet by sheet from the upper portion of the device by the ADF section 9906, and introduced to the document reading section 9902. After the image is read, the document is discharged to the outside of the device from the front face of the device. On the other hand, the recording sheet is printed with the image information in the recording section 9904, and discharged to the outside of the device from the rear face of the device.
Arrow X indicates a direction in which the hand scanner 9903 is attached/detached. Numeral 9907 denotes an opening for accommodating the hand scanner 9903, 9908 denotes a guide section for guiding the attachment/detachment of the hand scanner 9903, and 9909 denotes a positioning member disposed in the opening 9907. The positioning member 9909 is constituted of an elastic member, and engaged in a concave portion 9910 formed in the hand scanner 9903 to position the hand scanner 9903 in a predetermined position to the device 9901. For the books, magazines and unfixed-form documents which cannot be passed through the document conveying path H and the ADF section 9906, the hand scanner 9903 is detached from the device 9901, the document is manually scanned to read the image, and the image can be printed onto the recording sheet or transmitted.
As described above, by detachably attaching the hand scanner to the device, the books, magazines, and unfixed-form documents can be read. However, in the conventional constitution in which the recording sheets are discharged from the rear face of the device, there are respects to be improved such as “since the recording sheet is behind the device, it is hard to notice document received”, “it is hard to remove the recording sheet”, “a recording sheet discharging space is necessary in the rear of the device, and the installation area is enlarged”, and “it is difficult to perform the recording sheet jam handling”. Moreover, since the discharge ports of the document and recording sheet are in different places, in front and rear of the device, the operator has to perform different paper handlings with the recording sheets and the document, which is troublesome. Furthermore, in a disadvantageous respect, there is a possibility that the operator mistakes a sheet taking port.
The above-described reading device of so-called hand scanner system is widely used in which the reading section is detachably attached to the facsimile device body. The prior art is disclosed in Japanese Utility Model Publication No. 7-44118. As described above, by manually scanning the document with the hand scanner detached from the device body, the image can be read.
In the above-described prior art, since the reading section is exposed from the body, and can directly be detached, the following defects are caused.
When the document reading section is touched during the cleaning, or moving of the device body, the reading section tends to be easily detached from the body, or the normal conveying, or reading of the document cannot easily be performed, and reading defects such as the image deficiency by the position deviation of the document and reading section, and the image blur generated by the rising of the document and reading section tend to be easily caused.
Moreover, in the prior art, when the reading section is attached to the body, a special method is necessary, which comprises connecting engaging portions disposed on the reading section and body, rotating the reading section centering on the engaging portions, and engaging the reading section into an elastic member disposed on the body, so that the positions of the body and reading section are fixed. Therefore, the troublesome attaching method generates the attachment mistake of the reading section, and causes the above-described disadvantages.